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1.
A modified method for the determination of tributyl-, dibutyl-, and monobutyl-tin in fish and sediment samples is proposed. The samples are digested with hydrochloric acid and the butyltin compounds are extracted into a tropolone solution in pentane and pentylated by a Grignard reaction. The products are cleaned up by washing with a sodium hyrdoxide solution, dried over sodium sulphate, concentrated by evaporation and analysed by gas chromatography with flame photometric detection, using an interence filter at 610 nm. Problems peculiar to the fish and sediment samples are overcome by this improved clean-up procedure. The limit of detection for tributyltin in fish is 0.04 m?g g?1 and the reproducibility at 0.06 μg g?1, expressed as the relative standard deviation, is 6.8%. Contaminated sediment samples were found to contain the mixed methylbutyl-tin compounds Me2BuSn+ and MeBu2Sn+. 相似文献
2.
An accurate and sensitive multi-species species-specific isotope dilution GC–ICP–MS method was developed for the simultaneous
determination of trimethyllead (Me3Pb+), monomethylmercury (MeHg+) and the three butyltin species Bu3Sn+, Bu2Sn2+, and BuSn3+ in biological samples. The method was validated by three biological reference materials (CRM 477, mussel tissue certified
for butyltins; CRM 463, tuna fish certified for MeHg+; DORM 2, dogfish muscle certified for MeHg+). Under certain conditions, and with minor modifications of the sample pretreatment procedure, this method could also be
transferred to environmental samples such as sediments, as demonstrated by analyzing sediment reference material BCR 646 (freshwater
sediment, certified for butyltins). The detection limits of the multi-species GC–ICP–IDMS method for biological samples were
1.4 ng g−1 for MeHg+, 0.06 ng g−1 for Me3Pb+, 0.3 ng g−1 for BuSn3+ and Bu3Sn+, and 1.2 ng g−1 for Bu2Sn2+. Because of the high relevance of these heavy metal alkyl species to the quality assurance of seafood, the method was also
applied to corresponding samples purchased from a supermarket. The methylated lead fraction in these samples, correlated to
total lead, varied over a broad range (from 0.01% to 7.6%). On the other hand, the MeHg+ fraction was much higher, normally in the range of 80–100%. Considering that we may expect tighter legislative limitations
on MeHg+ levels in seafood in the future, we found the highest methylmercury contents (up to 10.6 μg g−1) in two shark samples, an animal which is at the end of the marine food chain, whereas MeHg+ contents of less than 0.2 μg g−1 were found in most other seafood samples; these results correlate with the idea that MeHg+ is usually of biological origin in the marine environment. The concentration of butyltins and the fraction of the total
tin content that is from butyltins strongly depend on possible contamination, due to the exclusively anthropogenic character
of these compounds. A broad variation in the butylated tin fraction (in the range of <0.3–49%) was therefore observed in different
seafood samples. Corresponding isotope-labeled spike compounds (except for trimethyllead) are commercially available for all
of these compounds, and since these can be used in the multi-species species-specific GC-ICP-IDMS method developed here, this
technique shows great potential for routine analysis in the future. 相似文献
3.
Maria Ochsenkühn-Petropoulou Georgia Poulea Georgios Parissakis 《Mikrochimica acta》1992,109(1-4):93-99
For the quantitative speciation of tributyltin, Bu3Sn+ (TBT), in the presence of dibutyltin, Bu2Sn2+ (DBT), monobutyltin, BuSn3+ (MBT), triphenyltin, Ph3Sn+ (TPT), and inorganic tin in water samples and sediments, an accurate, reproducible, simple and rapid electrochemical method was developed. After extraction of the organotin compounds with dichloromethane, TBT could be selectively determined as species by alternating current polarography directly in the organic phase without any derivatisation. The successful application of this technique could be proved by the results obtained by intercomparison exercises on TBT in water samples and sediments, organized by the Community Bureau of Reference (BCR). For the application of this technique to sea water samples a preliminary ion exchange separation of TBT from the major components of sea water was performed, achieving a detection limit for TBT in the ppt range. 相似文献
4.
An analytical method for determining the presence in air of volatile forms (e.g. chlorides) of tributyltin (TBT) and that of methylbutyltins Me nBu(4?n)Sn (n = 1–3) was developed and used to establish whether dredged harbour sediments contaminated with TBT served as sources of air pollution with respect to organotin compounds. The method was based on active sampling of the air being analysed and sorption of analytes onto Poropak‐N. Sorbed methylbutyltins were extracted with dichloromethane and analysed by gas chromatography using flame photometric detection. Other butyltins were converted into butyltin hydrides prior to analysis by gas chromatography. It was shown that TBT‐contaminated sediments from Marsamxett Harbour, Malta, placed in 0.5 l chambers through which air was displaced by continuous pumping for 11 days released mainly methylbutyltins, with concentrations (as tin) reaching maximum 48 h mean values of 8.7 (Me3BuSn), 22.1 (Me2Bu2Sn) and 93.0 ng m?3(MeBu3Sn) being measured. Other volatile forms of TBT, dibutyltin and monobutyltin were detected in the headspace air, but very infrequently and at much lower tin concentrations (<2 ng m?3). It was also shown that methylbutyltins dissolved in sea‐water ([Sn] = 0.2 to 400 ng l?1) were very difficult to exsolve from this medium, even on prolonged evaporation of the solutions using mechanical agitation and active ventilation. The results suggest that emission of methylbutyltins from contaminated sediments probably occurs only from the surface of the material. The environmental implications of these findings in the management of TBT‐polluted harbour sediments are discussed. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
5.
Recent reports from our laboratory on the occurrence of methylbutyltins in marine sediments and seawater suggest that these compounds are formed in the environment by the methylation of both tributyltin (TBT) and thatof its degradation products, i.e. dibutyltin and monobutyltin, to give MenBu(4?n)Sn for which n = 1, 2 and 3 respectively. We investigated the possibility of inducing methylation of TBT in seawater–sediment mixtures in experiments carried out in vitro using environmental materials collected from a yacht marina in Msida, Malta. Three water–sediment mixtures, which were shown to contain TBT, dibutyltin and monobutyltin but no other organotins, were spiked with tributyltin chloride (90 mg in 100 ml sea‐water/100 ml sediment); to one mixture was added sodium acetate and to another methanol, to act as possible additional carbon sources, and all mixtures were allowed to stand at 25 °C in stoppered clear‐glass bottles in diffused light for a maximum of 315 days. Speciation and quantification of organotins was performed using aqueous phase boroethylation with simultaneous solvent extraction followed by gas chromatography with flame photometric detection. The atmosphere inside the bottles quickly became reducing with abundant presence of H2S, and after an induction period of about 112 days, and only in the reaction mixture containing methanol, methyltributyltin (MeBu3Sn) was observed in both sediment (maximum concentration 0.87 µgSn g?1) and overlying water (maximum concentration 6.0 µgSn l?1). The minimum conversion yield of TBT into MeBu3Sn was estimated to be 0.3%. MeBu3Sn has a significantly lower affinity for sediment than TBT and, therefore, is more mobile in the marine environment, possibly also migrating into the atmosphere to generate a hitherto unsuspected flux of organotin into that phase. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
6.
Methyltin compounds (MeSn) which do not originate from man–made pollution are common in estuaries and particularly in salt marshes containing the marsh grass Spartina alterniflora. This study reports the results of experiments in which estuarine water containing S. alterniflora leaves is spiked with inorganic tin, and estuarine water alone is spiked with inorganic tin and MeSn. When decaying leaves are present, inorganic tin concentrations in the water decrease and there is a 10-fold increase in inorganic tin concentration in the leaves. This biosorption follows pseudo–first–order kinetics. MeSn3+ and Me2Sn2+ occur occasionally in the water. The Me2Sn2+ concentration decreases with time and the Me3Sn2+ concentration increases with time in S. alterniflora leaves. The results of estuarine water amended with inorganic tin and MeSn in the absence of leaves are quite different. The overall inorganic tin concentration decreases significantly during the experiment, the MeSn3+ concentration is approximately constant, and concentrations of Me2Sn2+ and Me3Sn+ increase. This means that net methylation of inorganic tin has occurred. We conclude that decaying S. alterniflora is likely to be important in the cycling of tin in salt marshes. 相似文献
7.
Potentiometric studies of the interaction of (Me2Sn)2+ and (Me3Sn)+ with 5′-guanosine monophosphate [(5′-HGMP)2?, abbreviated as (HL-1)2?] and guanosine [(HGUO), abbreviated as (HL-2)] in aqueous solution (I = 0.1 mol·dm?3 KNO3, 298.15 ± 0.1 K) were performed, and the speciation of various complex species was evaluated as a function of pH. The species that exist at physiological pH ~7.0 are Me2Sn(HL-1)/[Me2Sn(HL-2)]2+ (87.0/88.8 %), [Me2Sn(HL-1)(OH)]?/[Me2Sn(HL-2)(OH)]+ (3.0/0 %) and [Me2Sn(HL-1H?1)]/[Me2Sn(HL-2H?1)]2+ (9.4/6.6 %) for 1:1 dimethyltin(IV):5′-guanosine monophosphate/dimethyltin(IV): guanosine systems, whereas for the corresponding 1:2 systems, the species are Me2Sn(HL-1)/[Me2Sn(HL-2)]2+ (44.0/92.0 %), [Me2Sn(HL-1H?1)]/[Me2Sn(HL-2H?1)]2+ (5.0/6.0 %), Me2Sn(OH)2 (49.0/0 %), [Me2Sn(HL-1)(OH)]?/[Me2Sn(HL-2)(OH)]+ (1.5/2.0 %), and [Me2Sn(OH)]+ (1.0/0 %). For 1:1 trimethyltin(IV):5′-guanosine monophosphate/trimethyltin(IV):guanosine systems, only [Me3Sn(HL-1)]?/[Me3Sn(HL-2)]+ (99.9 %) are found at pH = 7.0, whereas for 1:2 systems, [Me3Sn(HL-1)]?/[Me3Sn(HL-2)]+ (49.8/100 %), Me3Sn(OH) (15.0/0 %) and [Me3Sn(HL-1)(OH)]2?/Me3Sn(HL-2)(OH) (0.2/0 %) are the species found. No polymeric species were detected. Beyond pH = 8.0, significant amounts of [Me2Sn(OH)]+, Me2Sn(OH)2, [Me2Sn(OH)3]? and Me3Sn(OH) are formed. Multinuclear (1H, 13C and 119Sn) NMR studies at different pHs indicated a distorted octahedral geometry for the species Me2Sn(HL-1)/[Me2Sn(HL-2)]2+ in dimethyltin(IV)-(HL-1)2?/(HL-2) systems and a distorted trigonal bipyramidal/distorted tetrahedral geometry for the species [Me3Sn(HL-1)]?/[Me3Sn(HL-2)]+ in trimethyltin(IV)-(HL-1)2?/(HL-2) systems. 相似文献
8.
Christopher Glidewell 《Journal of organometallic chemistry》1985,294(2):173-178
Molecular geometries and energies have been calculated, using the semi-empirical MNDO method for the closed-shell species SnMe4, Sn2Me6, and (SnMe3)+; and using the UHF-MNDO method for the radicals (SnMe4)+, (Sn2Me6)+ and SnMe3.. The radical cation (SnMe4)+ is calculated to have C3v skeletal symmetry, with a C2v isomer some 15 kJ mol?1 higher in energy. The dinuclear radical cation (Sn2Me6)+ is calculated to be a σ(SnSn) radical, of D3d skeletal symmetry: although the calculated Sn(5s) spin density is extremely low, the tin atoms are far from planarity. Calculated spin densities are compared with experimental hyperfine couplings. 相似文献
9.
R. Barbieri N. Bertazzi C. Tomarchio R.H. Herber 《Journal of organometallic chemistry》1975,84(1):39-46
Tetraphenylarsonium and tetramethylammonium salts of the complex anions Ph3Sn(N3)?2, Ph3Sn(N3)(NCS)?, Me2Sn(N3)2?4 and Ph2Sn(N3)2(NCS)2?2 have been synthesized, and the solid state configuration of the complex anions has been studied by Mössbauer and vibrational spectroscopies. Trigonal bipyramidal structures are advanced for the Ph3SnIV derivatives, with equatorial SnC3 and apical pseudohalide ligands, while the R2SnIV compounds are assumed to be trans-octahedral species. The NCS? ligands are observed to be N-bonded to SnIV. Conductance and PMR (for the Me2SnIV compound) data suggest the presence of the complex anions also in solution phases. 相似文献
10.
E. A. Belokon’ V. I. Pergushov D. A. Tyurin M. P. Egorov M. Ya. Mel’nikov 《High Energy Chemistry》2005,39(4):224-231
Charge transfer to matrix molecules was found to be the principal photochemical reaction of the radical cations Me4Sn+· and Me6Sn
2
+·
. It was shown that the difference in the localization of positive charge in the ground state of these radical cations (at the Sn-C bond in Me4Sn+· and at the Sn-Sn bond in Me6Sn
2
+·
) did not affect the pathways of their photochemical reactions.__________Translated from Khimiya Vysokikh Energii, Vol. 39, No. 4, 2005, pp. 267–274.Original Russian Text Copyright © 2005 by Belokon’, Pergushov, Tyurin, Egorov, Mel’nikov. 相似文献
11.
Open‐Chain and Cyclic As‐functionalized Stannylarsines: Synthesis, Reactions, and Structure tBu3SnAsH2 ( 1 ) reacts with MeLi to form the lithium compound tBu3SnAsHLi which reacts with tBu2SnCl2 to give the AsH‐functionalized bis(arsino)stannane tBu2Sn(AsHSntBu3)2 ( 2 ). Metallation of diarsadistannetane (tBu2SnAsH)2 ( 3 ) with two equivalents of tBuLi yields the dilithio compound (tBu2SnAsLi)2 which reacts with Me3SiCl or Me3SnCl to give the corresponding As,As′‐bis‐substituted diarsadistannetanes (tBu2SnAsSiMe3)2 ( 4 ) and (tBu2SnAsSnMe3)2 ( 5 ), respectively. The novel compounds are characterized by NMR (1H, 119Sn) and mass spectroscopy, ring compounds 4 and 5 further by X‐ray structure analysis. In the solid state both ring compounds contain molecules with planar tin‐arsenic rings and two trans‐configurated Me3Si‐ or Me3Sn‐ring substituents (space group P21/n (No. 14), Z = 2). 相似文献
12.
Dimitra Kovala-Demertzi Vaso N. Dokorou Adam Opolski Maria Zervou 《Journal of organometallic chemistry》2005,690(7):1800-1806
The organotin flufenamates [Me2(flu)SnOSn(flu)Me2]2 (1), [Bu2(flu)SnOSn(flu)Bu2]2 (2) and [Bu2Sn(flu)2] (3) have been prepared and structurally characterized by means of vibrational and NMR (1H, 13C and 119Sn) spectroscopy. The crystal structure of [Me2(flu)SnOSn(flu)Me2]2 (1) has been determined by X-ray crystallography. Three distannoxane rings are present to the dimeric tetraorganodistannoxane of planar ladder arrangement. The structure is centro-symmetric and features a central rhombus Sn2O2 unit with two additional tin atoms linked at the O atoms. Six-coordinated tin centers are present in the dimer distannoxane. This structure is self-assembled via π → π and C-H → π stacking interactions. Flufenamic acid and flufenamates were evaluated for antiproliferative activity in vitro. Among the compounds tested [Bu2(flu)SnOSn(flu)Bu2]2 (2) and [Bu2Sn(flu)2] (3) exhibited high cytotoxic activity against the cancer cell line A549 (non-small cell lung carcinoma). 相似文献
13.
New dinuclear organotin (IV) complexes, Me4Sn2L, Ph4Sn2L and Bu4Sn2L, have been synthesized from reaction of R2SnCl2 (R = Me, Ph and Bu) with a 2,2′‐bis‐substituted diphenylamine arοylidene hydrazone, H4L. The synthesized compounds were investigated by elemental analysis and infrared, 1H‐NMR and 119Sn‐NMR spectroscopy. The structures of H4L, Me4Sn2L and Bu4Sn2L were also confirmed by X‐ray crystallography. H4L molecules adopt (E)‐configuration and keto‐tautomeric form in the solid state. In all complexes, the bis‐hydrazone acts as a tetra‐anionic ligand with two contiguous ONO tridentate domains that coordinate the two R2Sn moieties in the enolate form. The coordination environments of both tin centers are five‐coordinate. DNA‐binding studies were performed by UV–Vis spectroscopy, and the results indicate that the synthesized compounds significantly interact with calf thymus‐DNA in the intercalative mode. The results of polymerase chain reaction assay show that all the compounds affect on amplification of DNA, and complexes are more effective than ligands. The in vitro cytotoxicity against the human breast cancer line (MCF7) was determined using the MTT assay, and H4L and the dibutytin complex showed higher activity. 相似文献
14.
《Polyhedron》1999,18(26):3567-3571
The aluminum and gallium dimethyl complexes, [BpBut,Me]AlMe2 and [BpBut,Me]GaMe2, are readily obtained by the reactions of [BpBut,Me]Tl with Me3Al and Me3Ga, respectively. [BpBut,Me]AlMe2 and [BpBut,Me]GaMe2 have been structurally characterized by X-ray diffraction, which indicates that the most noticeable difference in these otherwise very similar structures is the C–M–C bond angle, which increases from 118.9(3)° for [BpBut,Me]AlMe2 to 124.0(2)° for [BpBut,Me]GaMe2. 相似文献
15.
The complexes of two organic carboxylates (containing {O,O}-donor atoms) with Me2Sn(IV)Cl2, n-Bu2Sn(IV)Cl2, Bz2Sn(IV)Cl2, Oct2Sn(IV)O, Me3Sn(IV)Cl, n-Bu3Sn(IV)Cl, Ph3Sn(IV)Cl, Ph3Sn(IV)Cl, and Bz3Sn(IV)Cl having ligand-to-metal ratios of 1: 2 and 1: 1 were prepared by two different methods. The FT-IR spectra clearly demonstrated
that organotin(IV) moieties react with {O,O}-atoms of the ligands. It was found that in all cases the COO− group was acting as bidentate in the solid state. The 119Sn NMR data revealed that the organotin(IV) moiety has a tetrahedral geometry in non-coordinating solvents. The biological
activity of these compounds was compared with that of their precursors, and all the synthesized compounds show significant
antibacterial activity. The antifungal activity of the complexes against six plant pathogens has been estimated. The complexes
display marked toxicity against these fungi and are more fungitoxic than free acids. The compounds have also shown significant
cytotoxicity against Brine Shrimp (Artemia salina).
The article was submitted by the authors in English. 相似文献
16.
T. A. Kochina D. V. Vrazhnov I. S. Ignat’ev M. G. Voronkov 《Russian Journal of General Chemistry》2006,76(11):1774-1777
Transformation of the diethylsilylium cation Et2Si+H into ethyl-and dimethylsilylium ions EtSi+H2 and Me2Si+H in reactions with nucleophiles is induced by electron-donor compounds. Their activity increases in the order Bu2O < BuOH < (Me3Si)2O < C6H6 and is determined by the structure of the intermediate adduct and electron density distribution in it. Qualitative estimation shows that the affinity of the tritiated diethylsilylium cation Et2Si+T for a nucleophile increases in the order C6H6 < BuOH < Bu2O < (Me3Si)2O. The higher affinity of the Et2Si+H cation for hexamethyldisiloxane compared to dibutyl ether, at similar basicity of the nucleophiles, is attributable to the higher charge of the oxygen atom in (Me2Si)2O. 相似文献
17.
The equilibrium: 2 Bu2(CH2=CHCH2)SnCl⇌Bu2Sn(CH2=CHCH2)2 + Bu2SnCl2takes place when the allyltin chloride is stirred in water. This has been chosen as a model to understand the extent as well as the mechanistic pattways of the disproportionation reactions 2 R3SnX⇌R4Sn + R2SnX2 which are thought to occur in the aquatic environment. The behaviour of Bu2(CH2=CHCH2)SnCl has been studied in various media: water, water-acetone, water-ethanol and water-hexane. It has also been ascertained that Bu2(CH2=CHCH2)SnCI is a product arising at room temperature from the scrambling of Bu2Sn(CH2==CHCH2)2 and Bu2SnCI2 either neat, in organic solvents or also in the presence of water. Equilibrium [1] has been interpreted as arising from a bimolecular interaction between the electrophilic aquo-cation [Bu2(CH2=CHCH2)Sn(H2O)n]+ and the nucleophilic molecule Bu2(CH2=CHCH2)SnCl. Kinetic studies on R3SnMe/Me2SnX2 (X = Cl, NO3) systems in alcoholic solvents (R = Me, Et, n-Pr, i-Pr, n-Bu) support the assumption that, in dissociating media, redistribution processes can be promoted by ionic electrophilic species. 相似文献
18.
Nandu Bala Sharma Anirudh Singh Ram C. Mehrotra† 《Phosphorus, sulfur, and silicon and the related elements》2013,188(7):1527-1539
The interaction of Bu2Sn(OPri)2 with a trifunctional tetradentate Schiff base (LH3) (where H3L = HOC6H4CH═NCH3C(CH2OH)2) yields the precursor complex Bu2Sn(LH) 1, which, on equimolar reactions with different metal alkoxides [Al(OPri)3, Bu3Sn(OPri), Ge(OEt)4]; Al(Medea)(OPri) (where Medea = CH3N- (CH2CH2O)2); and Me3SiCl in the presence of Et3N], affords, respectively, the complexes Bu2Sn(L)Al(OPri)2 2, Bu2Sn(L)Al(Medea) 3, Bu2Sn(L)Bu3Sn 4, Bu2Sn(L)Ge(OEt)3 5, and Bu2Sn(L)SiMe3 6. The reactions of 2 with 2,5-dimethyl-2,5-hexanediol in a 1:1 ratio and with acetylacetone (acacH) in a 1:2 molar ratio afforded derivatives Bu2Sn(L)Al(OC(CH3)2CH2CH2C(CH3)2 O) 7 and Bu2Sn(L)Al(acac)2 8, respectively. All of the derivatives 1– 8 have been characterized by elemental analyses, molecular weight measurements, and spectroscopic [IR and NMR (1H, 119Sn, 29Si, and 27Al)] studies. 相似文献
19.
Andreas Wirth Ilona Lange Dagmar Henschel Oliver Moers Armand Blaschette Peter G. Jones 《无机化学与普通化学杂志》1998,624(8):1308-1318
Polysulfonylamines. CII. New Coordination Compounds Derived from Triorganyltin(IV) Dimesylamides and Uncharged Ligands: Mononuclear and Polynuclear Complexes with Molecular or Ionic Crystal Structures The purpose of this report is to draw attention to the remarkable versatility of the dimesylamides R3SnA [A– = (MeSO2)2N–; R = Me ( 1 a ) or Ph ( 1 b )] as precursors for pentacoordinate triorganyltin(IV) complexes belonging to four distinct structural types. Representative complexes were prepared by treating 1 a or 1 b in the appropriate molar ratios with unidentate thiourea or urea-type ligands or with the bidentate ligand [Ph2P(O)CH2]2 (DPPOE). The following compounds were characterized by X-ray analysis: [Me3Sn(A)(thiourea)] ( 2 a ; monoclinic, space group P21/n), [Ph3Sn(A)(tetramethylthiourea)] ( 2 b ; monoclinic, P21, two independent formula units), [Me3Sn(1-methylurea)2]+ · A– ( 3 a ; monoclinic, P21/c), [Ph3Sn(1,1-dimethylurea)2]+ · A– ( 3 c ; triclinic, P1), [{Ph3Sn(A)}2(μ-dppoe)] ( 4 ; triclinic, P1), [Ph3Sn(μ-dppoe)]nn+ · n A– · n MeCN ( 5 ; monoclinic, P21/c). The lattices of 2 a , 2 b and 4 contain discrete uncharged formula units which are mononuclear for 2 a and 2 b or dinuclear for 4 , whereas 3 a , 3 c and 5 have ionic structures featuring mononuclear cations for 3 a and 3 c or an infinite linear-polymeric cation for 5 . In all the structures, the tin atoms adopt trigonal-bipyramidal geometries, the apical positions being occupied in 2 a and 2 b by the S atom of the thiourea and one O atom of A–, in 3 a and 3 c by the O atoms of two urea-type ligands, in 4 by an O atom of the bridging DPPOE molecule and one O atom of A–, and in 5 by two phosphoryl O atoms from different bridging DPPOE ligands. In the structures of 2 a , 3 a and 3 c , the (thio)urea NH functions are connected to A– via intermolecular or interionic N–H … O and N–H … N hydrogen bonds. Crystals of [{Me3Sn(bipyH+ … A–)}2(μ-bipy)]2+ · 2 A– ( 6 ; monoclinic, C2/c) formed adventitiously in a reaction mixture containing 1 a and 4,4′-bipyridine. The rod-like supramolecular cation of 6 (length ca. 4 nm) is built up from two Me3Sn+ units bridged through bipy and unidentally coordinated by a monoprotonated bipy (= bipyH+), resulting in a trigonal-bipyramidal geometry around tin (N atoms apical); each of the terminal bipyH+ ligands forms an +N–H … N– hydrogen bond with one A–. 相似文献
20.
Stannylation Experiments with NH-functional Aminoiminophosphoranes. Synthesis and Structure of the Tricyclic Stannaphosphazenes [Me2Sn(tBu2PN)NH]2 and [nBu2Sn(Ph2PN)2NH]2 Aminoiminophosphoranes tBu2P(NH)NH2 ( 1 ) and (H2NPPh2)N(Ph2PNH) ( 2 ) react with diaminostannanes R2Sn(NEt2)2 by cyclocondensation to give cyclostannaphosphazenes [Me2Sn(tBu2PN)NH]2 ( 3 ) and [R2Sn(Ph2PN)2NH]2 ( 4 a , b ) ( a : R = Me, b : R = nBu). With 2 and Me3SnNEt2 the ring compound Me2Sn(Ph2PN)2NSnMe3 ( 5 ) besides Me4Sn is formed by per-N-stannylation and Sn-methyl group transfer. The crystal structures of 3 and 4 b were determined by X-ray structure analysis. 3 forms a planar heterotricyclus containing three four-membered rings with two pentacoordinated tin atoms (space group P 1 (No. 2); Z = 1). 4 b consists of a tricyclic molecule with two puckered six-membered rings and one planar four membered tin-nitrogen ring with two pentacoordinated tin atoms (space group P 1 (No. 2); Z = 1). 相似文献